To meet customer demand, the commercial printing industry requires the capability of producing spot colors accurately and consistently. Spot colors can be defined as a fixed set of colors which may be Pantone® colors, customer logo colors, colors in a customers proprietary marked patterns, or customer defined colors in the form of an index color table. Spot colors are often used, or can be used, for large background areas, which may be the most color critical portion of a particular page. Consistent color in these areas may determine the difference between success and failure in meeting customer requirements.
Often spot colors in a multicolor printing system are rendered with a gray component replacement (GCR). The GCR allows the use of 3 or more number of separations to produce the color. For example, a tri-color GCR approach is used in Xerox iGen3 printer with Pantone® Spot Color Calibration (SCC) feature. In tri-color GCR, only three separations such as CMY, CMK, MYK, and CMK are used to produce the spot color. A search algorithm such as the Automated Spot Color Editor (ASCE) based iterations are performed on each spot color of interest in a way that guarantees both consistency and accuracy. This approach nearly always renders spot colors with either min-K or max-K solution. However, there is no intermediate-K solution being offered. Appearance of spot colors may result in non-smooth or noisy rendering because of the differences in half tone structures present in each separation. These differences in half tone structures are created by the interactions among colors as a result of varying amounts of CMYK recipe, particularly with K separation.
Accordingly, what is needed in this art are increasingly sophisticated systems and methods for reducing noise induced by color mixing spot color recipe search such that a customer can find a balanced amount of CMYK recipe that not only gives accurate color but which also appears smooth and thus less noisy.